I was sitting one summer's afternoon at an open window (my bedroom) looking into a garden, when I was surprised to observe a large and rare species of spider run across the window-sill in a crouching attitude. It struck me the spider was evidently alarmed, or it would not have so fearlessly approached me. It hastened to conceal itself under the projecting ledge of the window-sill inside the room, and had hardly done so when a very fine large hunting wasp buzzed in at the open window and flew about the room, evidently in search of something. Finding nothing, the wasp returned to the open window and settled on the window-sill, running backwards and forwards as a dog does when looking or searching for a lost scent. It soon alighted on the track of the poor spider, and in a moment it discovered its hiding-place, darted down on it, and no doubt inflicted a wound with its sting. The spider rushed off again, and this time took refuge under the bed, trying to conceal itself under the framework or planks which supported the mattress. The same scene occurred here; the wasp now appeared to follow the spider by sight, but ran backwards and forwards in large circles like a hound. The moment the trail of the spider was found the wasp followed all the turns it had made till it came on it again. The poor spider was chased from hiding-place to hiding-place, out of the bedroom, across a passage, and into the middle of another large room, where it finally succumbed to the repeated stings inflicted by the wasp. Rolling itself up into a ball the wasp then took possession of its prey, and after ascertaining it could make no resistance, tucked it up under its _very long hind legs_, just as a hawk or eagle carries off its quarry, when I interposed and secured both for my collection. Mr. Belt, in his work already frequently quoted, gives the following account of a struggle which not unfrequently occurs between wasps and ants for the sweet secretion of 'frog-hoppers:'--